The present invention relates to means for confirming whether the preset data has been correctly stored in the battery-backup RAM of an electronic apparatus such as the programmable calculator, portable or hand-held computer, and personal computer when either replacing the battery or during storage of the unit.
Conventionally, the capacitance of a capacitor has been made available for the protection of memory while replacing the battery of an electronic apparatus. However, it is still uncertain whether memory has been securely maintained. In other words, the contents of such a conventional battery backup memory may be lost by evaporation if the operator spends a long time replacing the battery. In addition, when such a battery-operated electronic apparatus is stored without being used for a long while, the contents of the RAM may not remain constant.